Arrowhead Union High School is a comprehensive public high school located on 157 acres in the Town of Merton, Wisconsin. The union high school is located in western Waukesha County, "Lake Country," and serves the villages of Hartland, Chenequa, Merton, and Nashotah as well as the towns of Merton, Lisbon, Delafield, Oconomowoc, and Pewaukee and the city of Delafield.